xil CONTENTS. 



CHAPTER IV. 



Causes of the imperfection of the palseontological record Causes 

 of the absence of certain animals as fossils Unrepresented time 

 Unconformity, sequence of phenomena indicated by Lead- 

 ing examples of unconformity Thinning out of beds Sudden 

 extinction of animals Disappearance of fossils, * . . 56-70 



CHAPTER V. 



Conclusions to be drawn from fossils Age of rocks Mode of 

 origin of any fossiliferous bed Fluviatile, lacustrine, and 

 marine deposits Conclusions as to climate, . . . 71-76 



CHAPTER VI. 



Primary divisions of the Animal Kingdom Impossibility of a 

 linear classification Tabular view of the chief divisions of the 

 Animal Kingdom General succession and progression of organic 

 types, 77-94 



PART ILPALJEOZQQLOGY. 



CHAPTER VII. 



Zoological characters and chief divisions of the Protozoa Relations 

 of the Protozoa to time Characters of the Foraminifera 

 Variations of the test of the Foraminifera Distribution of the 

 Foraminifera in time r Classification of the Foraminifera 

 Types of Foraminifera %ozoon Canadense Receptaculites, 97-128 



CHAPTER VIII. 



Characters of the Radiolaria Polycystina General characters of 

 the Spongida Divisions of Sponges The Horny Sponges 

 The Calcispongise The Stromatoporoids Archseocyathus 

 Siliceous Sponges Hexactinellidee Lithistidse Literature of 

 Protozoa, - . . . . 129-151 



CHAPTER IX. 



General characters and chief divisions of the Ccelenterata Distribu- 

 tion in time of Coslenterate animals Orders of Hydrozoa not- 

 represented as fossils Fossil Medusee and Sea-blubbers 



